Self-centering jig



March 10, 1925.

G. H. SIMON SELF CENTERTNG JIG Filed March 27, 1922 Pie. 1 4.

2 Sheets-Sheet 1 INVENTOR/ GECDRGE H. SIMON AJ $04K ATTO 2N CY PatentedMan), 1925.

UNITED STATES GEORGE H. SEVION, OF COVINGTON, KENTUCKY.

SELF-CENTEBING J'IG.

Application filed March 27, 1922. Serial No. 547,102.

To all whom it may concern:

Be it' known that I, GEORGE H. SIMON, a citizen of the United States,residing at Covington, in the county of Kenton and State of Kentucky,have invented a certain new and useful Improvement in Self-CenteringJigs, of which. the following is a specification.

My invention relates to self centering jigs for drilling and reamingthrough round or cylindrical metal machine parts, such as shafts, bolts,boring and facing bars, etc.

The objects of my invention are toprovide simple and eflicient meansadapted to be easily and quickly adjusted to receive and hold varyingsizes of material to be operated on; to provide simple and convenientmeans for a large variety of drills and reamers used upon all standarddrilling machines, thereby dispensing with special machinery for thisclass of work, and to provide means which will insure absolute accuracyin the drilling or reaming operation.

My-invention consists in the parts and combination and arrangement ofparts and in the details of construction as herein set forth andclaimed.

In the drawings:

Fig. 1 is a plan view;

Fig. 2 a side elevation;

Fig. 3 a rear elevation;

Fig. i a vertical section taken on the line -4 of Fig. 1; and

Fig. 5 isometric view of the device.

In the embodiment of my invention as illustrated and which shows apreferred construction I provide abase 1 having end slots 2 to receivefastening bolts (not shown) whereby the jig is adapted to be firmlymounted upon a drill press. Suitable standards 3 and 4: spaced apartfrom each other extend upwardly from the base. A V-block 5 having aV-groove 6 in its under side is mounted and securely held in position onsaid standards by dowel pins 7 and 8 and screws 9, 10, 11 and 12respectively.-

The V-block is provided with a vertical bore 13 disposed concentric withsaid V-groove to receive and hold slip bushings 14: having holes 15 ofvarying sizes jherethrough to receive drills of different diameters andeach having a knurled head 16 whereby it is supported in said bore andmay be turned by hand when inserting and removingv 1t. A curved recess17 is ormed in one side of said head. Screw 18 is, mounted in the inFig. 1 and pushed downwardly, the head 12 enga ing curved recess 17-thereby permltting rnurled head 16 to pass below head 19 whereupon thebushing is turned to the position shown in Fig. 5 and the screw head 19is clamped down against knurled head 16 of' said bushing to hold itfirmly in position.

The slip bushings "are used to permit a large variety of sizes of drillsand reamers to be used. The jigs accuracy depends only upon the accuracywith which the V-block is made. When the V-block is accurately made thework in everyfinstance will be accurately centered andsecurely heldwhile being drilled or reamed. g I

A work holdingand clamping block 20 having retaining flanges 20which'extend over and engage the walls of said standards, is mounted toslide vertically therebetween. Said work holding and clamping block 20is provided with a raised work engaging surface 21 on its upper side andon its lower side is provided with a socket 22, the lower end wall ofwhich is screw threaded. A ball-nut 23 having a tubular flange 24 on itslower side is supported in said socket by thrust sleeve 25 screwedtherein and having inward bevel 26 upon its upper end to engage thelower part of ball-nut 23. A slight clearance 27 is provided between thetubular flange and thrust sleeve to permit the ball-nut to moverelatively to the clamping block while adjusting said clamping block tohold it in clamping engagement upon the work. Ball-nut 23 is providedwith several holes 23 and lock nut 35 is" I provide stop measuring gauge36 having a slotted arm 37 with a stem 38 adapted to abut one end ofthework and said arm is mounted upon spindle 39 slidably supported inhole 40 of standard 4 and is adapted to be moved horizontally thereinand held in any desired adjusted position by set screw 11. Spindle 39 isprovided near one end with head Or nut 42 engaging one side of slottedarm 37 which arm is held in the desired adjusted position by wing nut43.

To adjust the holding and clamping block to receive varying sizes ofwork to be operated upon, simply turn the ball-nut and lock nut up ordown upon eye bolt 28 by means of a spanner wrench. The ball-nut 23 isadapted to move in socket 22 to take care of the swivel caused by thecam shaft 30 in clamping or unclamping the work to I be operated upon.

' Thrust sleeve holds ball-nut 23 in position to give the work holdingand clamping block 20 its down stroke. It is held in position, afterproper adjustment is made.-

Spindle 39 is made long enough to give the gauge a wide range of adustment.-

2. In a self centering jig, a base having standards theron suitablyspaced apart, a V- bloek secured thereon and having a bore concentricwith the V in said V-block, a hollow holding and clamping blockvertically and slidably mounted between said standards, a hall-nutengaging said hollow holding and clamping block and having a tubularflange thereon, a thrust sleeve screwed into said hollowholding andclamping block to provide downward thrust of the ball-nut, an eye boltscrewed into said ball-nut, a lock nut on said eye bolt engaging saidflange to hold said eye bolt and ball-nut in fixed relation to eachother, a cam shaft mounted in said eye bolt and standards and having alever adapted to oscillate said cam shaft. whereby said holding andclamping block is moved into holding engagement with the wort: whenmoved into open position or into closed position, as desired,substantially as set'l'erth lznd for the purposes specified.

In a self'cei'itering jig, a base, a hold- Special advantages of this:jig are its sini ing and clamping block therein, means for plicity,convenience, rapidity and ease at operation with simple antlco11ve11ient provision for using any 's'ize of drill that can be used onany diameter-and any length of material within the range of the jig withabsolute accuracy in drilling through the exact center of the shaft orother stock which may be clamped therein.

It will be apparent that my invention is capable of some modificationwithout departure from its scope or spirit as defined in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a self centering jig, a base having standards thereon suitablyspaced apart, a V-block secured thereon and havinga bore concentric withthe V in said V-block, a hollow holding and clamping block verticallyand slidably mounted between said standards, a ball-nut engaging saidhollow hold ing and clamping block and having a tubular flange thereon,a thrust sleeve screwed into said hollow holding and clamping block toprovide downward thrust of the ball-nut, means for locking said thrustsleeve in adjusted position, an eye bolt screwed into said ball-nut andlocked therein, a cam shaft pivotally mounted in said standards andhaving its cam engaging the eye of said eye bolt, and means foroperating said cam shaft.

recess in one side of said flange and a screw' 'mounted in said V-blockand adapted to engage and hold said flanged bushing, suhstantially asset forth and for the purposes specified.

l. In a self centering jig, a base havingstandards thereon spaced apartfrom each other, a V-block secured on the top of said standards with aV-groove formed therein and a bore formed therethrough concentric withsaid V-groove, a holding and clamping block slidably mounted betweensaid standards, a ball-nut mounted in said holding and clamping block,an eye bolt, means to hold said ball-nut and eye bolt in fixed relationto each other, a shaft havinga shoulder thereon, a cam on said shaftadjacent said shoulder and adapted to engage the eye of said eye bolt,said shaft having a reduced end, a flanged sleeve in one of saidstandards adapted to receive said reduced end and a pin adapted tofastensaid reduced end and sleeve together and means for oscillating said camshaft.

GEORGE H. SIMON.

